Mechanism for actuating bar steadier



July 29, 1969 R. c. DoERR MECHANISM FOR. ACTUATING BAR STEADIER 4 sheets-sheet 1 Filed March 3. 1967 INVENTOR ROBERT C. 00E/9i? e, LM 6'- Affarney July 29, 1969 Filed March Z 4 Sheets-Sheet 2 m n n- Ul R INVENTOR R ROBERT 6. OOERR BM,5M

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Aflorney United States Patent O 3,457,758 MECHANISM FOR ACTUATING BAR STEADIER Robert C. Doerr, Ellwood City, Pa., assignor to United States Steel Corporation, a corporation of Delaware Filed Mar. 3, 1967, Ser. No. 620,407 Int. Cl. B21b 17/10; B21d 43/16 U.S. Cl. 72-209 5 Claims ABSTRACT OF THE DISCLOSURE 'In a bar and tube steadier for a seamless-tube mill, three pivotally mounted guide rolls are swung to positions open, around the bar and around the tube, respectively, by a rack and pinion actuated by a hydraulic cylinder. The latter has rst and second opposed pistons and rods, ports communicating with the respective cylinder ends, with one of the pistons and rods having a passage therethrough communicating with the space between the pistons. The guide rolls are moved away from and toward a bar or tube by admitting hydraulic fluid under pressure alternately to the first port and passage, respectively.

CROSS REFERENCES TO RELATED APPLICATIONS This invention is an improvement in the means for actuating a bar steadier more fully disclosed in the application of Christian H. Heine, Jr. for Steadier for Mandrel Bar and Tube Shell, Ser. No. 417,753, filed Dec. 1l, 1964, now Patent No. 3,358,490.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to an improved hydraulic cylinder mechanism adapted for actuating and positioning a workpiece or the like. More particularly, it relates to a hydraulic cylinder mechanism for actuating a -bar and tube steadier for a seamless-tube mill and the like.

Description of the prior art Seamless tube mills of known types include a long and relatively slender mandrel bar. A billet or shell is forced over the mandrel or plug carried thereon by opposed rolls. A `bar steadier is an arrangement for steadying the rotating bar before the pierced shell or tube emerges from the mill, for guiding and steadying the shell with the mandrel bar therein as the shell emerges from the mill and for opening to permit the shell to be picked out after bar removal therefrom.

In the Heine application a plurality of frames each has a plurality of shafts journaled therein. Each shaft pivotally mounts a guide roll. The guide rolls are spaced circumferentially of the axial path of a tube. Pinions are also mounted on the shafts. Means reciprocable on each frame are adapted to turn the pinions and to operate the guide rolls toward and away from the axial path of the tubes. A hydraulic cylinder actuates each reciprocable means. A pair of spacer means, reciprocable on the frame, are adapted alternately to limit movement of the reciprocable means whereby the guide rolls encompass the mandrel bar and tube, respectively. `In other prior art steadiers a variety of linkages connected to one or more hydraulic cylinders actuate the guide means to encompass the bar or the tube.

-In the Heine application and in other prior art, Where a hydraulic cylinder or cylinders actuate guide-means, the cylinders usually have a single piston and rod. In the Heine application the cylinder rod moves back and forth to sequentially open the rolls, close the rolls to encompass the bar, open the rolls, close the rolls to encompass 3,457,758 Patented July 29, 1969 ICC the tube and open the rolls. The roll opening between bar and tube steadying takes times, hence shortens each period wherein the bar and tube are steadied. This loss of steadying time is likewise a disadvantage in other prior art designs involving linkages and a plurality of hydraulic cylinders. A further disadvantage is the additional maintenance involved in the pair of spacer means in Heine and the linkages of the prior art.

SUMMARY In the Heine steadier a plurality of pivotally mounted guide rolls are reciprocated by a rack actuated by a hydraulic cylinder to encompass a bar or tube or to stand in an open position. The improved hydraulic cylinder has first and second opposed pistons and rods and first and second ports communicating with the respective cylinder ends. One of the pistons and rods has a passage therethrough communicating with the space between the pistons. A spacer means on each rod restricts the respective rod movement toward the tube path. Means supply low pressure and .high pressure fluid to and liuid exhaust from the first port and passage and the second port, respectively. Fluid underpressure, respectively, to the first port opens the rolls; simultaneously to the second port and passage closes the rolls adjacent the bar and simultaneously to the first and second port positions the rolls adjacent the tube.

The advantages of the improvement over the prior art include:

(l) A direct movement of the rolls from the bar to the tube-en-compassing positions takes less time; hence, the bar and tube are steadied for a longer period of time.

(2) The spacer means provide accurate positioning of the rolls adjacent bar and tube and operator-accessibility thereof for more rapid size changes.

(3) Maintenance is reduced by the elimination of a pair of spacer means, linkages and any additional hydraulic cylinders.

BRIEF DESCRIPTION OF THE DRAWING A complete understanding of the invention may be obtained from the following detailed description and explanation which refer to the accompanying drawings illustrating the present preferred embodiments. 11n the drawings:

FIGURE l is a plan view of a seamless-tube mill, with parts thereof shown schematically, -with the steadier apparatus and some of the actuating means of invention shown in different operating positions;

FIGURE 2 is a vertical side elevation of a steadier, partly in section, showing the position of cylinder components when the guide rolls encompass a mandrel bar;

FIGURE 3 is a vertical side elevation similar to FIG- URE 2 showing component positions when the guide rolls encompass a tube;

FIGURE 4 is a vertical side elevation similar to FIG- URE 2 showing component positions when the guide rolls are in an open position;

FIGURE 5 .is a vertical section taken on the line V--V of FIGURE 4; and

FIGURE 6 is a vertical side elevation, partly in section, of a modified form of a cylinder of invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detail to the drawings, FIGURE 1 shows piercer-mill rolls 10, 11 with a billet 12 lheilig pierced over a mandrel 13 and carried by a mandrel bar 14 as Ia shell or tube 15. The other end of bar 14 is rotatably secured in a thrust bearing in a carriage 16, reciprocable by means, not shown, on tracks 17. A thrust block 18 carries a latch 19. A plurality of guide-roll steadiers 20, 21 and 22 are spaced transversely of and adjacent to the axial path of bar 14 and shell 15. After piercing, latch 19 is disengaged, the guide rolls are opened, the tube being supported on roller conveyors 23 against stripper 24 as the carriage 16 is retracted to strip bar 14 from tube 15. The latter is kicked off transversely by a plurality of arms 25 mounted on a shaft 26 rotated by a motor 27. This operation may then be repeated.

As shown in FIGURES 1-5, each steadier 20, 21, 22 comprises a frame 28 and spaced, transverse vertical members 29, 30 mounted on a base 31. Three guide rolls 32, 33, 34, are spaced equally and circumferentially of the axial path, for movement toward and -away from this path. The rolls are pivotally mounted by pairs of rockers keyed to respective, longitudinal shafts 36, 37, 38, journaled in vertical members 29, 30. Pairs of pinion segments 39, 40, 41 are mounted concentrically on the respective shafts 36, 37, 38, outwardly of members 29, 30. Single pinion segments 39 mesh with dual-pinion segments 40, the latter being rotated by meshing with the teeth on a pair of reciprocable racks 42, as are single-pinion segments 41.

Each steadier 20, 21, 22 is actuated by an improved hydraulic cylinder 43, mounted on frame 28. A piston rod 44, carrying a piston 45, extends through a packing gland 46 in one end of cylinder 43 and is threaded centrally into a crosshead 47, which joins racks 42 at their inner ends. A pair of spacer means 48 mounted on or adjacent to rod 44 is preferably mounted on the extremities of crosshead 47. Each spacer means may be a set-screw arrangement comprising a head cap screw 49, threadedly reciprocable in crosshead 47, locked in place -by a jam nut 50 and carrying on its forward end a bearing plate 51. The latter is adapted to strike against a bearing-plate extension 52, mounted on vertical members 29, 30, respectively. This spacer means restricts movement of rod 44 and of the guide rolls toward said path and provides the amount or lack of clearance with which the rolls encompass the bar.

A second piston rod 53, in opposed relationship with respect to piston rod 44 and carrying a piston 54, extends through a packing gland in the opposite end of cylinder 43. The outer end of rod 53 is threaded at 56 for reciprocating a spacer means 57, which may be ra threaded nut 58 that can be locked in place by a setscrew 59. Spacer means 57 is adapted to strike against a sleeve 60 mounted on cylinder 43. This spacer means limits or restricts movement of piston 54 in the direction toward piston 45. A stop means 54a, for example, mounted in the cylinder, limits movement of piston 54 in the opposite direction. Spacer means 57 may strike against cylinder 43. It is preferred, however, to use .a sleeve 60 to avoid threaded portion 56 damaging packing gland 55.

First and second ports 61, 62 communicate respectively with the ends of cylinder 43. For a purpose to be described, a longitudinal -passage 63 is formed, for example, by drilling through rod 53 and piston 54 to communicate with a space 64 between opposed pistons 45, 54. As shown in the modification of FIGURE 6, a longitudinal passage 65 may be formed in piston rod 44 and piston 45, rather than in piston rod 53 and piston 54, to communicate with space 64. A passage 63 is preferred, since the hydraulicfluid hose thereto is shorter and somewhat more accessible.

As shown in FIGURE 1, a conventional, commercially available hydraulic-fluid system is provided to supply hydraulic fluid under pressure to any one or more th-an one port or passage and to exhaust fluid therefrom when not under pressure. For a purpose to be described, it is preferred to supply hydraulic fluid under a higher pressure to second port 62 than to first port 61 and either of passages 63 or 65. Fluid under a higher pressure is supplied to port 62 by a pump, not shown, toa line 66, a valve 67 and a line 68. When not under pressure, fluid is exhausted from port 62, by line 68, valve 67 and a line `69 to a sump, not shown. As shown schematically, valve 67 may be a CII solenoid operated, four-way spring-controlled hydraulic valve. Fluid under a lower pressure is supplied to port 61 by a pump, not shown, to a line 70, a valve 71 and a line 72. Fluid is exhausted from port 61 by line 72, valve 71 and a line 73 to a sump, not shown. Line 70 and valve 71 also supply uid under a lower pressure to a flexible line 74 and to either passage 63 or 65 and exhaust from the latter through line 74, valve 71 and line 73. As shown schematically, valve 71 may be a double, solenoid-operated four-way hydraulic valve.

As shown in FIGURE 4 and at steadier 21 in FIGURE 1, racks 42 may be retracted until the steadier rolls open, to permit a stripped shell to be ejected at the end of an operation. This is preferably done by admitting hydraulic fluid under pressure to first port 61, simultaneously exhausting fluid from second port 62 and passage 63, as indicated by the respective directional arrows in the lines and valves 67, 71.

As shown in FIGURE 2 and at steadier 20 in FIGURE l, racks 42 may be advanced until the steadier rolls close to encompass and to guide a mandrel bar just prior to a piercing operation. This is preferably done by admitting hydraulic fluid simultaneously to second port 62 and to passage 63, and simultaneously exhausting fluid from first port 61, as indicated by the respective arrows and Valve positions. Piston rod 53 is fully advanced as determined by spacer means 57 and by the higher fluid pressure to port 62. The lower fluid pressure to passage 63 Iand space 64 advances piston rod 44 until spacer means 48 thereon rests against vertical members 29, 30. Adjustment of spacer means 48 provides the amount or lack of clearance with which the rolls encompass the mandrel bar. A nominal clearance of about V32 between the bar and each roll has been found satisfactory as has a fluid pressure of about 800 p.s.i. .and 600 p.s.i. in lines 66 and 70, respectively.

As shown in FIGURE 3 and at steadier 22 in FIGURE 1, racks 42 may be retracted sufficiently from the FIG- URE 2, mandrel-bar-engaging position to encompass and to guide a hot tube subsequent to a piercing operation and just prior to tube arrival ahead of any steadier. This is preferably done by continuing hydraulic fluid pressure to second port 62, while simultaneously admitting hydraulci fluid to first port 61 and exhausting fluid from passage 63, as indicated by the respective arrows and valve positions. IPiston rod 53 continues in a fully advanced position. The lower fluid pressure to port 61 retracts piston rod 44 until piston 45 rests against piston 54, but cannot affect the gaging position of the latter with respect to positioning the rolls. Adjustment of spacer means 57 provides the amount of clearance with which the rolls encompass the hot tube. A nominal clearance of about 1/s between the tube and each roll has been found satisfactory to guide, yet minimize marking of the moving, hot tube. This rapid, accurate change in roll position from bar to tube, permitting longer bar and tube steadying, is an important ladvantage this improvement has over the prior art.

In the operation of a mill eqipped with steadiers and my actuating means, under manual control, for the purpose of explanation only, the operator, preferably stationed in a position where he can note the progress of the tube, observes its advance along mandrel bar 14. .I ust before the advancing end of tube 15 reaches steadier 22, the operator causes the steadier rolls to be retracated by positioning valves 67 `and 71 to admit hydraulic fluid to ports 61, 62 and to exhaust fluid from passage 63. The guide rolls now guide the tube in steadier 22. In like manner, the operator repeats the above-described operation with respect to steadiers 21 and 20. Thus, prior to and for a period after the engagement of billet 12 with bar 14, the bar is steadied at three spaced points along its length by steadiers 20, 21 and 22. Thereafter, as described, support is provided until the piercing operation is completed by successively changing from steadying the mandrel )bar to guiding the tube or shell.

After the piercing has been completed, the guide rolls are fully retracted by positioning valve 67 to exhaust fluid from port 62. The continuing uid pressure to port 61 causes piston 45 to retract, thereby retracting pistou 54 until it rests against stop 54a. The latch 19 is withdrawn and carriage 16 is retracted, withdrawing bar 14 from tube and causing mandrel 13 to drop off the end of bar 14. With bar 14 retracted, tube 15 may be supported on a plurality of roller conveyors 23 or on kickout arms 25 until motor 27 is operated to rotate shafts 26 and arms and thereby to eject the tube to an adjacent cooling bed or the like, not shown. Thereafter, the operator advances carriage 16 and ibar 14. A fresh mandrel 13 is placed on the end of bar 14 and the bar is advanced to its piercing position between rolls 10, 11. Latch 19 locks the carriage 16 against bridge 18. The guide rolls of all the steadiers are advanced to encompass bar 14 by positioning valves 67 and 71 to admit hydraulic uid to port 62 and passage 63 and to exhaust fiuid from port 61. After the next billet 12 is entered between rotating rolls 10, 11 the above-described operation is repeated.

The described apparatus and operation thereof represents the preferred embodiment of the invention` It is obvious the improved hydraulic-cylinder mechanism may be used to actuate a workpiece, other than a plurality of guide rolls, to locate the workpiece at spaced positions and at some position therebetween. Where precise clearance between guide rolls and a bar or tube is not required, or where it is preferred to guide or to steady a bar or tube by contact of the rolls therewith, the two spacer means may be omitted and the mechanism may be operated by hydraulic fluid at a uniform pressure throughout. The guide rolls may be reciprocated away from or toward a bar or tube by admitting hydraulic fluid under pressure alternately to the first port and passage, respectively.

The described mechanism embodies a relatively simple structure which is low in maintainance cost. The mechanism provides a maximum of rapid and precise steadying and guiding for both mandrel and tube. Also, the mechanism is accessible for making rapid size changes. Obviously, more than three steadiers may be aligned at a mill outlet. The improved apparatus may be used in the reeling, rotary rolling, elongating and high-mill operations associated with the seamless tube production process.

Although I have disclosed herein the preferred apparatus and operation of my invention, I intend to cover as well any change or modification therein which may be made without departing from the spirit and scope of the invention.

I claim:

1. In a steadier for a seamless-tube mill having a mandrel bar adapted to support tube shells as they move axially comprising a frame, a plurality of guide rolls pivotally mounted on said frame, spaced circumferentially of the path of the shells, means reciprocable on said frame, and means whereby said reciprocable means operates said guide rolls toward and away from said path, the improvement in said last-mentioned means comprising a hydraulic cylinder,

a first piston and rod in said cylinder adapted to reciprocate said reciprocable means,

a second reciprocable piston and rod in said cylinder,

said second piston and rod being vin opposed relationship with respect to said first piston and rod,

first and second ports communicating respectively with the -cylinder ends,

a passage through one of said pistons and rods communicating with the space between said opposed pistons,

means for supplying hydraulic fluid under pressure to y.thereof is restricted in the direction toward said first rod,

means for supplying hydraulic fluid at a higher pressure to said second port than to said first port and passage, .whereby when hydraulic fluid under said respective pressures is admitted simultaneously to said first and second ports said second piston restricts the movement of said first piston, thereby restricting the movement of said guide rolls away from said path.

4. Apparatus as defined in claim 3 characterized by a spacer means on said first rod whereby when hydraulic fiuid under said respective pressures is admitted simultaneously to said second port and said passage, the movement of said reciprocable means is restricted by said spacer means on said first rod, thereby restricting the movement of said guide rolls toward said path.

5. Apparatus for positioning a workpiece comprising a hydraulic cylinder,

a first piston and rod in said cylinder adapted to reciprocate a workpiece,

a spacer means on said rod adapted t0 restrict the movement of said workpiece to a first position,

a second reciprocable piston and rod in said cylinder,

said second piston and rod being in opposed relationship with respect to said first piston and rod,

a spacer means on said second rod whereby the movement thereof is restricted in the direction toward said first rod,

rst and second ports communicating respectively .with

the cylinder lends,

a passage through one of said pistons and rods communicating with the space between said opposed pistons,

means for supplying hydraulic fluid at a higher pressure to said second port than to said first port and passage,

means for exhausting said hydraulic Huid from each of said respective ports and passage, not simultaneously under pressure of hydraulic fluid,

whereby when hydraulic fluid under pressure is admitted to said first port said workpiece is moved to a second position, when hydraulic fluid under pressure iS admitted simultaneously to said second 4port and passage workpiece is moved to said first position and when hydraulic fluid under pressure is admitted simultaneously to said first and second ports said workpiece is moved to a third position intermediate said first and second positions.

References Cited UNITED STATES PATENTS 3,258,950 7/1966 Duro 72-370 3,358,490 12/1967 Heine 72-209 `MILTON S. MEHR, Primary Examiner US. Cl. X.R. 72-428 

